Mysterious Resurrection: the Beginning Sign in Guixi

The evil ghost has revived, and the world is like a prison. As soon as Wang Yan opened his eyes, he traveled to the mysterious world of recovery and became an ordinary student at No. 7 High School. Outside the door is a knocker who is about to knock on the door, but the dead ghost that comes from the gift package given by the most powerful ghost sign-in system is only a C-level ghost seal. How to face the knocker?